Field of the Invention
The present invention relates to a treatment instrument for an endoscope used in combination with an endoscope having a raising base formed at a distal end section of a channel, and an endoscope system including the treatment instrument for the endoscope.
Description of Related Art
When an endoscope is used to remove bile duct stones, since the duodenal papilla as an outlet port of the bile duct is narrowed, the stones may not be discharged as they are. In this case, the sphincter muscles are incised and the outlet port of the bile duct is widened to extract the stones with the treatment instrument for the endoscope passing through the endoscope, for example, a papillotome or the like as disclosed in Japanese Unexamined Patent Application, First Publication No. 2005-334000 and U.S. Pat. No. 7,371,237.
Since a position of a headband fold substantially coincides with a direction in which the bile duct extends around the duodenal papilla and the direction causes the blood vessel to be narrowed and the blood vessel does not easily bleed, in general, incision of the sphincter muscles is performed in the direction of the headband fold.
Here, in an endoscope appropriate for treatment of the liver and pancreas, when the endoscope is inserted into the duodenum to acquire an endoscope image, an image in which the bile duct is directed in substantially a twelve-o'clock direction is obtained. In such an endoscope, a raising base capable of elevating the papillotome in the twelve-o'clock direction is installed. Further, even in the papillotome used for incision of the sphincter muscles, when the papillotome protrudes from a distal end of the endoscope for the liver and pancreas, the papillotome is manufactured such that a direction of a knife portion (a treatment section) is automatically directed in substantially the twelve-o'clock direction of the endoscope screen.
Upon incision, the knife portion of the papillotome is stretched through manipulation of a near side. The knife portion is spaced apart from a sheath (a sheath section) and only the knife portion is pushed against the duodenal papilla. Accordingly, a large pressure occurs between the knife portion and a mucous membrane of the incised portion. When the raising base is driven while supplying electricity to the knife portion, a distal end of the papillotome is moved in the twelve-o'clock direction and the duodenal papilla is incised.
When the bile duct has a morphological feature or the like, when peripheral organs such as the duodenum or the like are narrowed, when a patient has received a surgical operation on a peripheral organ such as the duodenum or the like in the past, or the like, the direction of the bile duct in the vicinity of the duodenal papilla may be different from the twelve-o'clock direction of the endoscope screen.
Here, the papillotome of the related art is provided to easily perform the incision even in a direction other than the twelve-o'clock direction on the endoscope screen, and a torque transmission member configured to transmit a rotational torque from a hand is installed. Accordingly, the papillotome is configured to transmit a rotational torque for turning a proximal end side of the sheath about an axis to a distal end of the knife portion.